To overcome the problem of mismatched voltage levels between parallel-connected low voltage photovoltaic (PV)
arrays and the higher grid voltage, a hybrid boost three level dc-dc converter is developed based on three level inverter with
the traditional single phase diode clamping. Only one inductor, two capacitors in series, and those power switches and diodes,
which are easy to be integrated, are used for establish the topology with transformerless high voltage gain. The operation
principle of the topology is analyzed, and then the pulse width modulation (PWM) control method is obtained according to
the switching functions about the output pulse voltages of both half-bridges. Therefore, the converter can not only operate
with high voltage gain, but also make the duty cycles of power switches closer to 0.5. A feedforward closed loop control
operation is proposed such that even in varying input the converter is capable of giving a constant output. Finally an
experimental is set up in the laboratory for open loop control operation. All experimental results verify the feasibility of the
circuit and validity of the PWM control method.
AC - AC power conversions were traditionally done by using thyristor power controllers, phase angle control or by
integral cycle control, but had low PF and other disadvantages. Variable voltage, variable frequency high power conversions
are nowadays use DC link and Matrix converters, with higher efficiency and better regulation. But in situations where only
voltage regulation is required and the circuit need to be simple and less complicated, directed PWM AC-AC converters are
more preferred, due to reduced size and components. This project presents the design and simulation of a new type of AC-AC
converter which can operate as traditional non-inverting buck and boost converters, and inverting buck-boost converter as
well. This converter uses six unidirectional current flowing and bidirectional voltage blocking switches, implemented by six
reverse blocking IGBTs or series MOSFET-diode pairs, two input and output filter capacitors, and one inductor. It has no
shoot-through problem of voltage source (or capacitor) even when all switches are turned-on and therefore; PWM dead times
are not needed resulting in high quality waveforms, and solves the commutation problem without using bulky and lossy RC
snubbers or dedicated soft-commutation strategies. It has smaller switching losses because; only two switches out of six are
switched at high frequency during each half cycle of input voltage, and it can use power MOSFETs as body diode never
conducts, making it immune from MOSFET failure risk..
Torque Ripple Minimization of a BLDC Motor Drive by Using Electronic Commutat...AI Publications
Brushless DC motors are having a major problem with harmonics in torque. The variations in speed and production of noise should be minimized by using proper topologies. BLDC motors have been gaining attention from different Industrial and domestic appliance manufacturers, because of their high efficiency, high power density and easy maintenance and low cost. This paper presents a three phase BLDC motor with low cost drive to be driven without DC link capacitor. The proposed technique uses an electronic commutation and operates the machine exclusive of the intermediate DC link capacitor. The designing of Brushless DC motor drive system along with control system for torque ripple minimization, speed controller and current controllers are presented using MATLAB / SIMULINK and results are evaluated.
Performance of Six-Pulse Line-Commutated Converter in DC Motor Drive ApplicationZunAib Ali
This paper presents the speed control of DC motor using six pulse controlled rectifier. The
conventional Proportional Integral (PI) control is used for firing angle control. The armature current is fed
back and compared with reference current representing desired speed values. The proposed system is
simulated using SimPowerSystem and Control System Matlab toolbox. The time domain plot of reference
and actual armature current are shown in results section. The results are satisfactory with deleterious effect
on input current. The frequency plot of input current is provided to show the harmonic contents, generated
as a result of control operation.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
AC - AC power conversions were traditionally done by using thyristor power controllers, phase angle control or by
integral cycle control, but had low PF and other disadvantages. Variable voltage, variable frequency high power conversions
are nowadays use DC link and Matrix converters, with higher efficiency and better regulation. But in situations where only
voltage regulation is required and the circuit need to be simple and less complicated, directed PWM AC-AC converters are
more preferred, due to reduced size and components. This project presents the design and simulation of a new type of AC-AC
converter which can operate as traditional non-inverting buck and boost converters, and inverting buck-boost converter as
well. This converter uses six unidirectional current flowing and bidirectional voltage blocking switches, implemented by six
reverse blocking IGBTs or series MOSFET-diode pairs, two input and output filter capacitors, and one inductor. It has no
shoot-through problem of voltage source (or capacitor) even when all switches are turned-on and therefore; PWM dead times
are not needed resulting in high quality waveforms, and solves the commutation problem without using bulky and lossy RC
snubbers or dedicated soft-commutation strategies. It has smaller switching losses because; only two switches out of six are
switched at high frequency during each half cycle of input voltage, and it can use power MOSFETs as body diode never
conducts, making it immune from MOSFET failure risk..
Torque Ripple Minimization of a BLDC Motor Drive by Using Electronic Commutat...AI Publications
Brushless DC motors are having a major problem with harmonics in torque. The variations in speed and production of noise should be minimized by using proper topologies. BLDC motors have been gaining attention from different Industrial and domestic appliance manufacturers, because of their high efficiency, high power density and easy maintenance and low cost. This paper presents a three phase BLDC motor with low cost drive to be driven without DC link capacitor. The proposed technique uses an electronic commutation and operates the machine exclusive of the intermediate DC link capacitor. The designing of Brushless DC motor drive system along with control system for torque ripple minimization, speed controller and current controllers are presented using MATLAB / SIMULINK and results are evaluated.
Performance of Six-Pulse Line-Commutated Converter in DC Motor Drive ApplicationZunAib Ali
This paper presents the speed control of DC motor using six pulse controlled rectifier. The
conventional Proportional Integral (PI) control is used for firing angle control. The armature current is fed
back and compared with reference current representing desired speed values. The proposed system is
simulated using SimPowerSystem and Control System Matlab toolbox. The time domain plot of reference
and actual armature current are shown in results section. The results are satisfactory with deleterious effect
on input current. The frequency plot of input current is provided to show the harmonic contents, generated
as a result of control operation.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
discusses about the reduction of commutation torque ripple in BLDC motor and various convention methods and the proposed method for 2 level inverter and 3 level inverter
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
VSC BASED HVDC SYTEM DESIGN AND PROTECTION AGAINST OVER VOLTAGESIJERD Editor
High Voltage Direct Current system based on voltage source converter (VSC-HVDC) is becoming
more effective solution for offshore wind plants and supplying power to remote regions. In this paper, the
control of a VSC-based HVDC system (VSC-HVDC) is described. Based on this control strategy, appropriate
controllers utilizing PI controllers are designed to control the active and reactive power at each end station.The
operation performance of a voltage source converter (VSC) based HVDC (VSC-HVDC system) system is
explained under some characteristic faulted conditions with and without protection measures. A protection
strategy is proposed to enhance the continuous operation performance of the VSC-HVDC system. The strategy
utilizes a voltage chopper to suppress over-voltages on the DC side of the VSC. Digital simulation is done to
verify the validity of the proposed control strategy and protection strategy
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Analysis and characterization of different high density on chip switched capa...Aalay Kapadia
Power converter is a key component in micro-scale energy harvesting systems. Micro-scale energy harvesting has become an increasingly viable and promising area for powering ultra-low power systems. Switched-capacitor (SC) power converters that use capacitors as energy storage elements offer much better power density than switched-inductor counterparts and are thus attractive in low-power area-constrained applications. Switched-capacitor (SC) converters have shown tremendous promise in this regard due to favorable device utilization and scaling trends, and the emergence of high-density silicon-compatible capacitor technologies. With the rising integration levels used to increase digital processing performance, there is a clear need for multiple independent on-chip supplies in order to support per-IP or block power management. The growing demand for both performance and battery life in portable consumer electronics requires SoCs and power management circuits to be small, efficient, and dynamically powerful. This project first reviews various design techniques for implementing high density On-chip Switched-capacitor (SC) power converters and secondly suggests the best technique to solve aspects of power converter design: Area Density, Power Consumption & Efficiency.
A Five – Level Integrated AC – DC ConverterIJTET Journal
This paper presents the implementation of a new five – level integrated AC – DC converter with high input power factor and reduced input current harmonics complied with IEC1000-3-2 harmonic standards for electrical equipments. The proposed topology is a combination of boost input power factor pre – regulator and five – level DC – DC converter. The single – stage PFC (SSPFC) approach used in this topology is an alternative solution to low – power and cost – effective applications.
A hybrid converter topologies which can supply simultaneously AC as well as DC from a single DC source. The new Hybrid Converter is derived from the single switch controlled Boost converter by replacing the controlled switch with voltage source inverter (VSI). This new hybrid converter has the advantages like reduced number of switches as compared with conventional design having separate converter for supplying AC and DC loads, provide DC and AC outputs with an increased reliability, resulting from the inherent shoot through protection in the inverter stage. For controlling switches PWM control, based upon unipolar Sine-PWM is described.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
This presentation was presented to Dr. Chongru Liu in North China Electric Power University,Beijing,China by Mr. Aazim Rasool. This presentation will help to understand the control of HVDC system. Animations are not working like ppt. so I apologize on this.
Modeling and Analysis of Transformerless High Gain Buck-boost DC-DC ConvertersIAES-IJPEDS
This paper proposes a transfomerless switched capacitor buck boost converter model, which provides higher voltage gain and higher efficiency when compared to the conventional buck boost converter. The averaged model based on state- space description is analyzed in the paper. The simulation results are presented to confirm the capability of the converter to generate high voltage ratios. The comparison between the proposed model and the traditional model is also provided to reveal the improvement. The proposed converter is suitable for for a wide application which requires high step-up DC-DC converters such as DC micro-grids and solar electrical energy.
SIMULATION ANALYSIS OF CLOSED LOOP DUAL INDUCTOR CURRENT-FED PUSH-PULL CONVER...Journal For Research
The current electronic devices require DC power source, which is taken from a battery or DC power supply. DC-DC converter is utilized to get regulated dc voltage from unregulated one. Switched mode power supply (SMPS) are commonly used in industrial applications, because of more advantages compared to linear power supply. In SMPS we have isolated and non-isolated converters, where isolated converters are frequently used, in order to get more voltage with multiple outputs. So among different isolated converters, push-pull converter is chosen for micro converter applications to obtain high voltage conversion ratio by using HF transformer, due to their better utilization of transformer. New methodology of control is implemented for making ZVS and ZCS at same time and to reduce the number of switches in the secondary side of dual inductor CFPP converter, which is a voltage doubler circuit. This becomes the solution for problem identification. Thus this converter with soft-switching reduces the switching losses.The current-fed push-pull converters are used in many applications like photo-voltaic (PV) power converters for boosting the output voltage. Push-pull converter is chosen for micro converter applications, to obtain high voltage conversion ratio by using high frequency (HF) transformer, due to their better utilization of transformer. This deals with the design of dual inductor CFPP converter, where zero voltage switching (ZVS) and zero current switching (ZCS) is achieved for the primary side of the converter by using secondary switches. Primary side switches are controlled by closed loop control topology. The secondary side is made with voltage doubler to obtain high voltage. Open loop and closed loop control of dual inductor current fed push pull converter simulation is finished by MATLAB/SIMULINK and their outcomes are analyzed.
discusses about the reduction of commutation torque ripple in BLDC motor and various convention methods and the proposed method for 2 level inverter and 3 level inverter
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
VSC BASED HVDC SYTEM DESIGN AND PROTECTION AGAINST OVER VOLTAGESIJERD Editor
High Voltage Direct Current system based on voltage source converter (VSC-HVDC) is becoming
more effective solution for offshore wind plants and supplying power to remote regions. In this paper, the
control of a VSC-based HVDC system (VSC-HVDC) is described. Based on this control strategy, appropriate
controllers utilizing PI controllers are designed to control the active and reactive power at each end station.The
operation performance of a voltage source converter (VSC) based HVDC (VSC-HVDC system) system is
explained under some characteristic faulted conditions with and without protection measures. A protection
strategy is proposed to enhance the continuous operation performance of the VSC-HVDC system. The strategy
utilizes a voltage chopper to suppress over-voltages on the DC side of the VSC. Digital simulation is done to
verify the validity of the proposed control strategy and protection strategy
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Analysis and characterization of different high density on chip switched capa...Aalay Kapadia
Power converter is a key component in micro-scale energy harvesting systems. Micro-scale energy harvesting has become an increasingly viable and promising area for powering ultra-low power systems. Switched-capacitor (SC) power converters that use capacitors as energy storage elements offer much better power density than switched-inductor counterparts and are thus attractive in low-power area-constrained applications. Switched-capacitor (SC) converters have shown tremendous promise in this regard due to favorable device utilization and scaling trends, and the emergence of high-density silicon-compatible capacitor technologies. With the rising integration levels used to increase digital processing performance, there is a clear need for multiple independent on-chip supplies in order to support per-IP or block power management. The growing demand for both performance and battery life in portable consumer electronics requires SoCs and power management circuits to be small, efficient, and dynamically powerful. This project first reviews various design techniques for implementing high density On-chip Switched-capacitor (SC) power converters and secondly suggests the best technique to solve aspects of power converter design: Area Density, Power Consumption & Efficiency.
A Five – Level Integrated AC – DC ConverterIJTET Journal
This paper presents the implementation of a new five – level integrated AC – DC converter with high input power factor and reduced input current harmonics complied with IEC1000-3-2 harmonic standards for electrical equipments. The proposed topology is a combination of boost input power factor pre – regulator and five – level DC – DC converter. The single – stage PFC (SSPFC) approach used in this topology is an alternative solution to low – power and cost – effective applications.
A hybrid converter topologies which can supply simultaneously AC as well as DC from a single DC source. The new Hybrid Converter is derived from the single switch controlled Boost converter by replacing the controlled switch with voltage source inverter (VSI). This new hybrid converter has the advantages like reduced number of switches as compared with conventional design having separate converter for supplying AC and DC loads, provide DC and AC outputs with an increased reliability, resulting from the inherent shoot through protection in the inverter stage. For controlling switches PWM control, based upon unipolar Sine-PWM is described.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
This presentation was presented to Dr. Chongru Liu in North China Electric Power University,Beijing,China by Mr. Aazim Rasool. This presentation will help to understand the control of HVDC system. Animations are not working like ppt. so I apologize on this.
Modeling and Analysis of Transformerless High Gain Buck-boost DC-DC ConvertersIAES-IJPEDS
This paper proposes a transfomerless switched capacitor buck boost converter model, which provides higher voltage gain and higher efficiency when compared to the conventional buck boost converter. The averaged model based on state- space description is analyzed in the paper. The simulation results are presented to confirm the capability of the converter to generate high voltage ratios. The comparison between the proposed model and the traditional model is also provided to reveal the improvement. The proposed converter is suitable for for a wide application which requires high step-up DC-DC converters such as DC micro-grids and solar electrical energy.
SIMULATION ANALYSIS OF CLOSED LOOP DUAL INDUCTOR CURRENT-FED PUSH-PULL CONVER...Journal For Research
The current electronic devices require DC power source, which is taken from a battery or DC power supply. DC-DC converter is utilized to get regulated dc voltage from unregulated one. Switched mode power supply (SMPS) are commonly used in industrial applications, because of more advantages compared to linear power supply. In SMPS we have isolated and non-isolated converters, where isolated converters are frequently used, in order to get more voltage with multiple outputs. So among different isolated converters, push-pull converter is chosen for micro converter applications to obtain high voltage conversion ratio by using HF transformer, due to their better utilization of transformer. New methodology of control is implemented for making ZVS and ZCS at same time and to reduce the number of switches in the secondary side of dual inductor CFPP converter, which is a voltage doubler circuit. This becomes the solution for problem identification. Thus this converter with soft-switching reduces the switching losses.The current-fed push-pull converters are used in many applications like photo-voltaic (PV) power converters for boosting the output voltage. Push-pull converter is chosen for micro converter applications, to obtain high voltage conversion ratio by using high frequency (HF) transformer, due to their better utilization of transformer. This deals with the design of dual inductor CFPP converter, where zero voltage switching (ZVS) and zero current switching (ZCS) is achieved for the primary side of the converter by using secondary switches. Primary side switches are controlled by closed loop control topology. The secondary side is made with voltage doubler to obtain high voltage. Open loop and closed loop control of dual inductor current fed push pull converter simulation is finished by MATLAB/SIMULINK and their outcomes are analyzed.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Fuzzy Logic Controller Based High Frequency Link AC-AC Converter For Voltage ...IJTET Journal
Abstract—In this paper, an advanced high frequency link AC-AC Push-pull cycloconverter for the voltage compensation is proposed in order to maintain the power quality in electric grid. The proposed methodology can be achieve arbitrary output voltage without using large energy storage elements. So that the system is more steadfast and less costly compared with the conventional inverter topology. Additionally, the proposed converter does not contain any line frequency transformer, which reduces the cost further. The control scheme for the push pull cycloconverter employs the fuzzy logic controller based sinusoidal pulse width modulation (SPWM) to accomplish better performance on voltage compensation, like unbalanced voltage harmonics elimination. The simulation results are given to show the effectiveness of the proposed high frequency link AC-AC converter and fuzzy logic controller based SPWM technology
Interleaved Boost Converter with Cumulative Voltage Unitpaperpublications3
Abstract: A boost converter is a DC to DC converter with an output voltage greater than the source voltage. But it produces large input current ripple. In order to improve the efficiency of the boost converter and reduce the ripple current, an interleaved boost converter is used. An interleaved boost converter consists of several boost converters connected in parallel with switching frequency and a phase shift of 180˚. A new interleaved high step-up DC-DC converter with the circuit of cumulative voltage unit (CVU) is presented in this work. This converter is suitable for the high gain applications. Only two switches are required to form the boosting path and the interleaved topology. Each CVU module can share common diodes to reduce the number of the components and step up the voltage gain. The interleaved structure in the input end can reduce the power loss in each current-owing component and the input current ripple. The interleaved boost converter with voltage summation unit can be verified by using MATLAB/SIMULINK.
Keywords: Cumulative voltage unit, Boost converter, Interleaved boost converter, Voltage Stress.
Title: Interleaved Boost Converter with Cumulative Voltage Unit
Author: Shyma H, Prof. Smitha Paulose, Prof. Leela Salim
ISSN 2349-7815
International Journal of Recent Research in Electrical and Electronics Engineering (IJRREEE)
Paper Publications
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
A High Step Up Hybrid Switch Converter Connected With PV Array For High Volt...ijitjournal
T
his paper
presents
a
ste
p up DC
-
to
-
DC converter with
hybrid switch capacitor technique having
high
voltage conversion ratio with small
switch voltage stress
. The converter is suitable for the applications
where high voltage conversion is required. The proposed
DC
-
DC converter
has low voltage ratted
MOSFET switch and is connected to PV array to get high output voltage at small duty ratios.
Hence it has
high efficiency.
The principles of operations and the theoretical analysis are presented in this paper.
All the
simulations are
done in MATLAB
-
SIMULINK Environment and
results were obtained with voltage
conversion ratio of 4.
Transformerless DC-DC Converter Using Cockcroft-Walton Voltage Multiplier to ...IJERA Editor
In the present scenario the use of transformer for high voltages in converter circuit reduces the overall operating
efficiency due to leakage inductance and use of transformer also increases the operational cost. . Therefore the
proposed system is implemented with transformer less DC-DC converter so as to obtain high DC voltage with
the use of nine stage Cockcroft-Walton (CW) voltage multiplier. The proposed converter operates in CCM
(continuous conduction mode), so that the converter switch stress, the switching losses are reduced. The DC
voltage at the input of the proposed model is low and is boosted up by boost inductor (Ls) in DC-DC converter
stage and performs inverter operation. The number of stages in CW-voltage multiplier circuit is applied with
low input pulsating DC (AC Voltage) voltage where it is getting converted to high DC output voltage. The
proposed converter switches operates at two independent frequencies, modulating (fsm) andalternating (fsc)
frequency. The fsm operates at higher frequency of the output while the fsc operates at lower frequency of the
desired output voltage ripple and the output ripples can be adjusted by the switch Sc1 and Sc2. The regulation of
the output voltage is achieved by controlling the Duty ratio.The simulation is carried over by the MATLABSIMULINK.
Fuzzy Control Based Quadrupler Boost ConverterIJSRD
A voltage quadruple boost converter is presented. This converter is used to obtain higher voltage gain and reduces the voltage stress across the switches and diodes. These voltage multipliers are used in high voltage, low current applications such as for accelerating purpose in a cathode ray tube and also this converter topology is advanced than previous dc-dc converters. Voltage quadruple converter uses parallel-input series-output connection. Comparing with two phase interleaved boost converter one can see that two more capacitors and two more diodes are added so that during the energy transfer period partial inductor stored energy is stored in one capacitor and partial inductor stored energy together with the other capacitor store energy is transferred to the output to achieve much higher voltage gain. However, the proposed voltage gain is twice that of the interleaved two-phase boost converter. Simulation of the converter is carried out using MATLAB/SIMULINK software. The converter is simulated using fuzzy logic control and also the experimental setup was done.
A Non-isolated Hybrid Boost Three Level DC-DC Converter with High Step-up Con...IJSRD
Nowadays renewable energy sources are increasingly used to meet the world’s increasing demand for energy. In grid connected photovoltaic (PV) generation systems, a single PV array can supply lower dc voltage. In order to connect PV array to the grid, the voltage has to be boosted to higher levels that is demanded by the grid side. A hybrid boost three level dc-dc converter based on traditional single phase three level diode clamped inverter can be used to connect low voltage PV array to the high voltage grid. Only one inductor, two capacitors in series, and those power switches and diodes, which are needed to establish the topology with high voltage gain. Pulse width modulation (PWM) control method is used for the control of power switches. Power switches of this converter works with duty cycles closer to 0.5. This hybrid three level dc-dc converter works with high gain without a transformer or coupled inductor. In addition, voltages across the capacitors in series are balanced in both steady and dynamic states. Therefore capacitor voltage balancing circuitry can be avoided. Also, blocking voltages of the power switches are half of the output dc voltage. This hybrid converter is suitable for PV generation systems connected to the grid with parallel- connected low-voltage PV arrays.
Extremely high duty cycle of boost converter may result in higher conduction losses. To achieve a high
conversion ratio without operating at extremely high duty ratio, some converters based on transformers or coupled
inductors or tapped inductors have been provided. However, the leakage inductance in the transformer, coupled
inductor or tapped inductor will cause high voltage spikes in the switches and reduce system efficiency. A novel
single switch cascaded dc-dc converter of boost and buck boost converters have extended voltage conversion ratio
to d/(1-d)2. The features of the converter are high voltage gain; only one switch for realizing the converter, the
number of magnetic components is small etc. So comparing with other topologies cascaded converter is more
effective. Simulation of the converter for a dc input voltage and fixed duty cycle was done, and the same was
verified experimentally for a low input voltage. The software used for simulation was MatlabR2014a
This paper presents a step up DC-to-DC converter with hybrid switch capacitor technique having high voltage conversion ratio with small switch voltage stress . The converter is suitable for the applications where high voltage conversion is required. The proposed DC-DC converter has low voltage ratted MOSFET switch and is connected to PV array to get high output voltage at small duty ratios. Hence it has high efficiency. The principles of operations and the theoretical analysis are presented in this paper. All the simulations are done in MATLAB- SIMULINK Environment and results were obtained with voltage conversion ratio of 4.9.
Transformer Less Voltage Quadrupler Based DC-DC Converter with Coupled Induct...IJPEDS-IAES
In this paper a voltage quadrupler dc-dc converter with coupled inductor
and π filter is presented. The use of the coupled inductor reduces the high
leakage inductance which is present in a transformer enabled converter.
The output ripples in the converter is reduced by providing a π filter.
The interleaved voltage quadrupler is used in this system in order to boost the
output voltage. The voltage multiplier improves the output voltage gain.
The main advantage of this system is more voltage gain when compared with
the transformer eneabled circuit and the overall efficiency of the system is
improved. The circuit is simple to control. As a final point of this research,
the simulation and the hardware investigational results are presented to
demonstrate the effectiveness of this proposed converter.
The power electronics device which converts DC power to AC power at required output voltage and frequency level is known as inverter. Multilevel inverter is to synthesize a near sinusoidal voltage from several levels of dc voltages. In order to maintain the different voltage levels at appropriate intervals, the conduction time intervals of MOSFETS have been maintained by controlling the pulse width of gating pulses. In this paper single phase to three phase power conversion using PWM technique. The simulation is carried out in MATLAB/Simulink environment which demonstrate the feasibility of proposed scheme.
International Journal of Engineering Research and Applications (IJERA) aims to cover the latest outstanding developments in the field of all Engineering Technologies & science.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
High gain dc-dc step up converters have been used in renewable energy systems, for example, photovoltaic grid connected system and fuel cell power plant to step up the low level dc voltage to a high level dc bus voltage. If the conventional boost converter is to meet this demand, it should be operated at an extreme duty cycle (duty cycle closes to unity), which will cause electromagnetic interference, reverse recovery problem and conduction loss at the power switches. This paper proposes a class of non-isolated dc-dc step up converters which provide very high voltage gain at a small duty cycle (duty cycle < 0.5). Firstly, the converter topologies are derived based on active switched inductor network and combination of active and passive switched inductor networks; secondly, the modes of operation of proposed active switched inductor converter and combined active and passive switched inductor converter are illustrated; thirdly, the performance of the proposed converters are analyzed mathematically in details and compared with conventional boost converter. Finally, the analysis is verified by simulation results.
Similar to [IJET V2I5P10] Authors: Vinith Das, Dr. Babu Paul, Prof. Elizabeth Seba stian (20)
These days we have an increased number of heart diseases including increased risk of heart attacks. Our proposed system users sensors that allow to detect heart rate of a person using heartbeat sensing even if the person is at home. The sensor is then interfaced to a microcontroller that allows checking heart rate readings and transmitting them over internet. The user may set the high as well as low levels of heart beat limit. After setting these limits, the system starts monitoring and as soon as patient heart beat goes above a certain limit, the system sends an alert to the controller which then transmits this over the internet and alerts the doctors as well as concerned users. Also the system alerts for lower heartbeats. Whenever the user logs on for monitoring, the system also displays the live heart rate of the patient. Thus concerned ones may monitor heart rate as well get an alert of heart attack to the patient immediately from anywhere and the person can be saved on time.This value will continue to grow if no proper solution is found. Internet of Things (IoT) technology developments allows humans to control a variety of high-tech equipment in our daily lives. One of these is the ease of checking health using gadgets, either a phone, tablet or laptop. we mainly focused on the safety measures for both driver and vehicle by using three types of sensors: Heartbeat sensor, Traffic light sensor and Level sensor. Heartbeat sensor is used to monitor heartbeat rate of the driver constantly and prevents from the accidents by controlling through IOT.
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splitting the inputs and reduce is the process of integrating the output of map’s input. Recently, in medical fields
the experienced problems like machine failure and fault tolerance while processing the result for the scanned
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Text mining has turned out to be one of the in vogue handle that has been joined in a few research
fields, for example, computational etymology, Information Retrieval (IR) and data mining. Natural
Language Processing (NLP) methods were utilized to extricate learning from the textual text that is
composed by people. Text mining peruses an unstructured form of data to give important
information designs in a most brief day and age. Long range interpersonal communication locales
are an awesome wellspring of correspondence as the vast majority of the general population in this
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turns into a typical practice to not compose a sentence with remedy punctuation and spelling. This
training may prompt various types of ambiguities like lexical, syntactic, and semantic and because of
this kind of indistinct data; it is elusive out the genuine data arrange. As needs be, we are directing
an examination with the point of searching for various text mining techniques to get different
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contemplates in online networking have utilized text investigation and text mining methods to
identify the key topics in the data. This study concentrated on examining the text mining
contemplates identified with Facebook and Twitter; the two prevailing web-based social networking
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Colorectal cancer (CRC) has potential to spread within the peritoneal cavity, and this transcoelomic
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Heat transfer in pipes is a distinctive kind of procedure employed in heat exchanger which transfers great
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Now-a-day’s pedal powered grinding machine is used only for grinding purpose. Also, it requires lots of efforts
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[IJET V2I5P10] Authors: Vinith Das, Dr. Babu Paul, Prof. Elizabeth Seba stian
1. International Journal of Engineering and Techniques - Volume 2 Issue 5, Sep – Oct 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 71
Closed Loop Controlled Hybrid Boost Three Level DC-DC
Converter with High Voltage Gain for PV Systems
Vinith Das1
, Dr. Babu Paul2
, Prof. Elizabeth Sebastian3
1 Department of Electrical and Electronics Engineering, Mar Athanasius College of Engineering, India
2 Department of Electrical and Electronics Engineering, Mar Athanasius College of Engineering, India
3 Department of Electrical and Electronics Engineering, Mar Athanasius College of Engineering, India
I. INTRODUCTION
Both photovoltaic (PV) and wind
power generations have become important
parts of renewable energy sources, due to
worldwide exhausted fossil fuel and worlds
demand for clean energy. In grid-connected
PV generation systems, a single PV array can
only supply lower dc voltage, but higher
voltage level is demanded for the grid-
connected side. Therefore, the mode of PV
arrays in series has been adopted to offset the
differential voltage levels between dc bus and
grid side. Unfortunately, low voltage PV
arrays are always subjected to inevitable
cloud, dust, shadow, and so on, which will
limit the output current of the total PV arrays,
and then the efficiency of the entire PV
generation system will be degraded. Naturally,
the other mode of PV arrays in parallel has
also been proposed, and the power generation
level can be improved by extending the
parallel connected PV arrays flexibly.
Considering parallel connected PV
configuration, the most important problem is
that the low dc bus voltage has to be boosted
to high voltage. Therefore, high step-up dc-dc
converters are introduced between low
voltage parallel connected PV arrays and the
demanded high voltage grid connected side
for the voltage conversion. When converters
operate with high step-up gains, high output
voltage would be sustained completely by the
power switches in conventional boost two-
level converters. The classical boost three-
level converters could reduce half of the
voltage stress, but it requires extreme duty
cycles of power switches which limits its
voltage gains and switching frequency
because of the shorter turn off time of the
power switches in each switching period.[1]-
[3]
RESEARCH ARTICLE OPEN ACCESS
Abstract:
To overcome the problem of mismatched voltage levels between parallel-connected low voltage photovoltaic (PV)
arrays and the higher grid voltage, a hybrid boost three level dc-dc converter is developed based on three level inverter with
the traditional single phase diode clamping. Only one inductor, two capacitors in series, and those power switches and diodes,
which are easy to be integrated, are used for establish the topology with transformerless high voltage gain. The operation
principle of the topology is analyzed, and then the pulse width modulation (PWM) control method is obtained according to
the switching functions about the output pulse voltages of both half-bridges. Therefore, the converter can not only operate
with high voltage gain, but also make the duty cycles of power switches closer to 0.5. A feedforward closed loop control
operation is proposed such that even in varying input the converter is capable of giving a constant output. Finally an
experimental is set up in the laboratory for open loop control operation. All experimental results verify the feasibility of the
circuit and validity of the PWM control method.
Keywords- Photovoltaic system(PV system), Hybrid boost converter
2. International Journal of Engineering and Techniques - Volume 2 Issue 5, Sep – Oct 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 72
Cascaded boost converters are also
used to extend the voltage gain and duty
cycles, but one obvious disadvantage is that it
requires more number of separate inductors,
and the power switch of the last power stage
cannot avoid the output voltage stress. Many
researchers have put their studies on step-up
converters with coupled inductor in recent
years, which has the transformer function to
extend the voltage gain and duty cycles.
Although the voltage stress of power switches
is low, the output power level is limited and
the input current ripple is large due to the
single phase structure. Therefore, the idea of
interleaved boost converters with switched
capacitors came into being. However, more
switched capacitor cells are required to obtain
a high voltage gain. An interleaved high step-
up converter integrated with winding-cross-
coupled inductors and voltage multiplier cells
is presented, but it sponges on more coupled
inductors which are not easy to be integrated
or designed in standardization. In addition,
the duty cycles of the power switches inclines
to 1, due to the increased voltage gain.[4]-[7]
A hybrid boost three-level dc-dc
converter with closed loop control is proposed
in this project, taking the topology established
without a transformer or coupled inductors
into account. It is composed of only one
inductor, two output capacitors in series, and
other power semiconductor components,
which are easy to be integrated. This
converter can not only realize high step-up
gain, but also avoid extreme duty cycles. The
deduction of the topology synthesis with
closed loop control is explained in this project
and simulation results are obtained. Also, a
prototype is set up for the open loop control,
and the effective experimental results are
obtained.
II. HYBRID BOOST THREE LEVEL DC-
DC CONVERTER
This topology mainly consists of 4
control switches. The interleaved conduction
property and hybrid switching property are
clubbed together here. Apart from the control
switches, the circuit requires 8 diodes. Also, a
boost inductor and 2 output capacitors in
series are implemented in the circuit.
Fig. 1 Hybrid Boost Three Level DC-DC Converter
Fig. 1 shows the circuit diagram. As
already mentioned, there are 4 control
switches Q1 - Q4, 8 diodes D1 - D4 and Dc1 -
Dc4, 2 output capacitors Cf1 and Cf2 and the
boost inductor Lf . As shown in the figure, it
is basically an interconnected circuit with two
half bridges with hybrid switching. In this
way the interleaved conduction property can
be implemented. If the half bridges are
operated individually, each requires a separate
inductor and 2 capacitors; on a whole 2
inductors and 4 capacitors would be required.
Additional advantage of the interconnection is
that a single inductor and 2 capacitors can be
shared by both the half bridges. Consider the
points a, b, p and g shown in the Fig.1. g is
the ground terminal taken for the load RL. The
output of half bridge I is voltage across a and
g, Vag. The output of half bridge II is across b
and g, Vbg. Thus the resultant of these outputs
of half bridges acts as an output voltage pulse
Vab across the load.
= −
The capacitors Cf1 and Cf2 filter this
output voltage pulse and generates constant
DC voltage across the load, Vo = Vpg. Values
3. International Journal of Engineering and Techniques
ISSN: 2395-1303
of the capacitors determine the voltage ripple
in the output DC voltage.
A. MODES OF OPERATION
The modes of operation can be
explained by considering the switching of
control switches and its consequences. For a
particular switching frequency, switches Q
and Q2 are operated for first half cycle, and,
switches Q1 and Q2 are operated for second
half cycle. Pulse width of gate signal to Q
greater than that to Q2. Similarly, pulse width
of gate signal to Q4 is greater than that to Q
Switches Q1 and Q4 are complementary, ie.,
they operate with same pulse width but in
different half cycles. Same is the case for Q
and Q3. Based on the switching states, there
are 5 modes of operation for the circuit. Fig.2
shows the mode of operation, in which the
waveforms of the gate signals to the switches
and corresponding change in Vag, V
are shown.
Fig. 2 Modes of Operation
1) Mode I: In this mode, all the control
switches will be switched off. Diodes D
will be in conduction. The inductor is
discharging and both the capacitors are
charging. In a single period of gate signal, this
mode occurs in three times. Here, V
Vbg = 0, and Vab = Vag - Vbg = V
shows the region of operation where
unshaded portion represents the region. Fig.
3(b) shows the current flow in the circuit.
International Journal of Engineering and Techniques - Volume 2 Issue 5, Sep –
http://www.ijetjournal.org
of the capacitors determine the voltage ripple
The modes of operation can be
considering the switching of
control switches and its consequences. For a
particular switching frequency, switches Q1
are operated for first half cycle, and,
are operated for second
half cycle. Pulse width of gate signal to Q1 is
. Similarly, pulse width
is greater than that to Q3.
are complementary, ie.,
they operate with same pulse width but in
different half cycles. Same is the case for Q2
itching states, there
are 5 modes of operation for the circuit. Fig.2
shows the mode of operation, in which the
waveforms of the gate signals to the switches
, Vbg and Vab
n this mode, all the control
switches will be switched off. Diodes D1 - D4
in conduction. The inductor is
ing and both the capacitors are
charging. In a single period of gate signal, this
mode occurs in three times. Here, Vag = Vo,
= Vo. Fig. 3(a)
s the region of operation where
unshaded portion represents the region. Fig.
3(b) shows the current flow in the circuit.
Fig. 3 Mode I (a) Region of Operation (b) Current Flow Diagram
2) Mode II: In mode II operation, Q
switched on. Diodes Dc2, D3 and D
conducting. This mode operates in the first
half cycle. The inductor is discharging.
Capacitor Cf1 is discharging and Capacitor C
is charging. Half bridge outputs, V
Vbg = 0, and Vab = Vo/2. Fig. 4 shows the
mode II operation.
Fig. 4 Mode II (a) Region of Operation (b) Current Flow Diagram
Fig. 5 Mode III (a) Region of Operation (b) Current Flow Diagram
3) Mode III: In mode III operation, Q
are switched on. Diodes D3 and D
conducting. The inductor is charging and the
output voltage to the load is supplied by
discharging the capacitors. Vag
and Vab = 0. Fig. 5 shows the mode III
operation.
4) Mode IV: Mode IV is a complementary
action of mode II, which operates in the other
half cycle. Here Q4 is switched on. Diodes
Dc3, D1 and D2 will be conducting. The
– Oct 2016
Page 73
Fig. 3 Mode I (a) Region of Operation (b) Current Flow Diagram
operation, Q1 is
and D4 will be
conducting. This mode operates in the first
half cycle. The inductor is discharging.
is discharging and Capacitor Cf1
is charging. Half bridge outputs, Vag = Vo/2,
/2. Fig. 4 shows the
Fig. 4 Mode II (a) Region of Operation (b) Current Flow Diagram
Fig. 5 Mode III (a) Region of Operation (b) Current Flow Diagram
In mode III operation, Q1 and Q2
and D4 will be
conducting. The inductor is charging and the
output voltage to the load is supplied by
= 0, Vbg = 0,
= 0. Fig. 5 shows the mode III
Mode IV is a complementary
, which operates in the other
is switched on. Diodes
will be conducting. The
4. International Journal of Engineering and Techniques
ISSN: 2395-1303
inductor is discharging, Cf1 is charging and
Cf2 is discharging. Vag = Vo, Vbg = V
Vab = Vo/2. Fig. 6 shows the mode IV
operation.
Fig. 6 Mode IV (a) Region of Operation (b) Current Flow Diagram
5) Mode V: As in the previous case, mode V is
a complementary action of mode III operation
in the other half cycle. Q3 and Q4 are switched
on. Diodes D1 and D2 will be conducting. The
inductor is charging and the output voltage to
the load is supplied by discharging the
capacitors. Vag = Vo, Vbg = Vo, and V
Fig. 5 shows the mode V operation.
Fig. 7 Mode V (a) Region of Operation (b) Current Flow Diagram
B. VOLTAGE GAIN EQUATION
The voltage gain equation is derived
with the help of the energy balance equation
of the inductor. Consider the operating modes
waveforms in fig. 2. ton1, ton2, ton3
the turn on time periods of switches Q
Q3 and Q4 respectively. d1, d2, d3
the corresponding duty ratios. As mode II and
IV, and, mode III and V are complementary,
ton1 = ton4 (d1 = d4) and ton2 = ton3 (d
the total time period. IL is the average
inductor current.
The energy stored in the inductor,
= × × 2 ×
International Journal of Engineering and Techniques - Volume 2 Issue 5, Sep –
http://www.ijetjournal.org
is charging and
= Vo/2, and
/2. Fig. 6 shows the mode IV
Fig. 6 Mode IV (a) Region of Operation (b) Current Flow Diagram
As in the previous case, mode V is
a complementary action of mode III operation
are switched
will be conducting. The
r is charging and the output voltage to
the load is supplied by discharging the
, and Vab = 0.
Fig. 5 shows the mode V operation.
Fig. 7 Mode V (a) Region of Operation (b) Current Flow Diagram
The voltage gain equation is derived
with the help of the energy balance equation
of the inductor. Consider the operating modes
and ton4 are
the turn on time periods of switches Q1, Q2,
3 and d4 are
the corresponding duty ratios. As mode II and
IV, and, mode III and V are complementary,
(d2 = d3). T is
is the average
× 2
(by considering complementary actions in the
total time period, equation in mode I is
doubled)
The energy transferred from the inductor,
= ( − ) × ×
2
−
2
− × × ( 1
where,
( 1 2) = ( 1 −
Assuming the ideal case, energy transferred
from the inductor will be equal to the energy
stored in it.
=
Putting these equations together,
=
− ( 1
But ton1 = d1.T and ton2 = d
voltage gain M = Vo/Vin. Therefore,
=
1
1 − ( 1
From the above equation, it is clear
that extreme duty cycle for the switches are
not needed for high voltage gain, it can be
obtained from duty ratios close to 0.5. The
equation shows that at 0.5 duty ratio, the gain
will be infinity.
IV. CLOSED LOOP CONTROL
For a given input, the required output
can be obtained by switching with particular
duty cycles. This is the open loop control. But
for PV systems, input is always varying as the
intensity of sunlight varies continuously. So
open loop control is not reliable, closed loop
control is required to obtain constant output
even if the input is varying. This section
explains about a closed loop control for the
hybrid boost three level DC-DC converter
– Oct 2016
Page 74
(by considering complementary actions in the
total time period, equation in mode I is
The energy transferred from the inductor,
− 1 × 2
2) × 2
2)
Assuming the ideal case, energy transferred
from the inductor will be equal to the energy
Putting these equations together,
2)
= d2.T. And also,
. Therefore,
2)
From the above equation, it is clear
that extreme duty cycle for the switches are
not needed for high voltage gain, it can be
obtained from duty ratios close to 0.5. The
duty ratio, the gain
IV. CLOSED LOOP CONTROL
For a given input, the required output
can be obtained by switching with particular
duty cycles. This is the open loop control. But
for PV systems, input is always varying as the
f sunlight varies continuously. So
open loop control is not reliable, closed loop
control is required to obtain constant output
even if the input is varying. This section
explains about a closed loop control for the
DC converter.
5. International Journal of Engineering and Techniques
ISSN: 2395-1303
A. PWM STRATEGY
The basic idea for the closed loop
control implemented here is that changing the
gain value for varying inputs to obtain a
constant output. For that, duty cycles of the
switching pulses are varied according to the
change in input voltage. As there are 4
different gate signals, 4 different calculations
are required from a single value. For that, a
specific PWM strategy is proposed and it is
explained below.
Fig. 8 PWM Strategy
Fig. 8 shows the PWM strategy. For
making the calculations simple, the
carrierwave taken is a triangular wave with
peak amplitudes +1 and -1. d1, d2
are the duty cycles of Q1, Q2, Q
respectively. For obtaining these gate signals,
the carrier wave is compared with constant
values c01, c02, c03 and c04 as shown in the
figure. For making d1 - d4 and d
complementary, c01 and c04 are equal values
having opposite signs; same is the case for c
- c03. When magnitude of carrierwave is
greater than c01 and c04, gate signals for Q
and Q4 are generated. When magnitude of
carrierwave is less than c02 and c
signals for Q2 and Q3 are generated, for
giving a 180 degree shift.
From the figure it is found that,
1 = 0.5 − (0.5 × 01)
4 = 0.5 (0.5 × 04)
The 4 gate signals must be generated
with a single value control, say 'c', for reliable
operation. For that the 4 constants c
International Journal of Engineering and Techniques - Volume 2 Issue 5, Sep –
http://www.ijetjournal.org
The basic idea for the closed loop
control implemented here is that changing the
gain value for varying inputs to obtain a
constant output. For that, duty cycles of the
switching pulses are varied according to the
e. As there are 4
different gate signals, 4 different calculations
are required from a single value. For that, a
specific PWM strategy is proposed and it is
Fig. 8 shows the PWM strategy. For
simple, the
carrierwave taken is a triangular wave with
, d2, d3 and d4
, Q3 and Q4
respectively. For obtaining these gate signals,
the carrier wave is compared with constant
as shown in the
and d2 - d3 pairs
are equal values
having opposite signs; same is the case for c02
. When magnitude of carrierwave is
, gate signals for Q1
are generated. When magnitude of
and c03, gate
are generated, for
)
)
The 4 gate signals must be generated
with a single value control, say 'c', for reliable
operation. For that the 4 constants c01, c02, c03
and c04 must be given in terms of c. Assume
c02 = c and c01 = 0.5c, c03 = -c and c
So the above equations changes to,
1 = 0.5 − (0.25 ×
4 = 0.5 − (0.25 ×
Then the equation for voltage gain changes to,
=
1
1 − ( 1 2)
=
1
1 − 0.5 − (0.25 × ) 0.5
=
4
3
The above equation shows that the
voltage gain M can be adjusted by
single value c, instead of adjusting the 4 gate
signals separately. Here a carrierwave of peak
+1 and -1 is taken. Practically it is available
with logic 0 and 1 (0V and +5V). To consider
these changes, the carrier waveform shown in
figure 4.1 has to be proportionally shifted
upwards to make the peak points 0 and +5.
Then c01, c02, c03 and c04 to c1, c
given below,
1 = 2.5 (1.25 ×
4 = 2.5 − (1.25 ×
Only the relation between c and
individual constants changes due to
proportional shifting. The voltage gain
equation remains same, M = 4/(3c). For
closed loop control, a relation between c and
Vin has to be found. Looking into the gain
equation,
=
4
3
where k = 4/(3Vo). As output voltage has to
be taken as constant, value of k will
be constant. Thus a linear relationship
between c and Vin is obtained. For the
variations in input voltage, control can be
implemented in this converter using this
equation to get a constant output. Here ideal
case is taken and a linear relationship between
c and Vin with origin 0 is obtained. In
practical case, the equation will have an
additional intercept value.
– Oct 2016
Page 75
must be given in terms of c. Assume
c and c04 = -0.5c.
hanges to,
× )
× )
Then the equation for voltage gain changes to,
5 − (0.5 × )
The above equation shows that the
voltage gain M can be adjusted by controlling
single value c, instead of adjusting the 4 gate
signals separately. Here a carrierwave of peak
1 is taken. Practically it is available
with logic 0 and 1 (0V and +5V). To consider
these changes, the carrier waveform shown in
has to be proportionally shifted
upwards to make the peak points 0 and +5.
, c2, c3 and c4 as
× )
× )
Only the relation between c and
nts changes due to
proportional shifting. The voltage gain
equation remains same, M = 4/(3c). For
closed loop control, a relation between c and
Vin has to be found. Looking into the gain
= 4/(3Vo). As output voltage has to
be taken as constant, value of k will
be constant. Thus a linear relationship
between c and Vin is obtained. For the
variations in input voltage, control can be
implemented in this converter using this
constant output. Here ideal
case is taken and a linear relationship between
with origin 0 is obtained. In
practical case, the equation will have an
6. International Journal of Engineering and Techniques - Volume 2 Issue 5, Sep – Oct 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 76
V. SIMULATION MODEL AND
RESULTS
Simulation is done for both open loop
and closed loop control. It is done with
practical settings to get an idea of variation in
ideal theoretical concepts and practical
scenario. IGBTs are the controlled switches
used for the simulation. For the open loop
control, a PV system with 50V is taken as
input. The converter has to boost it to 600V
(M = 12). Maximum inductor current through
the inductor is 50A. Load is 1k resistor.
Switching frequency taken is 5kHz.
Voltage gain M = 12, so constant c is,
=
4
3 ×
=
4
3 × 12
=
1
9
Taking current ripple, ΔIL in the inductor as 7%
of inductor current,
= 0.07 × = 0.07 × 50 = 3.5
Taking output ripple, ΔVo as 2% of output
voltage,
= 0.02 × = 0.02 × 600 = 12
Output current, Io is,
= =
600
1000
= 0.6
For a boost converter, design equation for the
boost inductor Lf is,
=
( − )
× ×
=
50(600 − 50)
3.5 × 5000 × 600
= 2.6
The effective duty cycle for the converter, D
is,
= 1 −
1
= 1 −
1
12
= 0.9167
The output filter capacitor value, Cf is,
=
×
×
=
0.6 × 0.9167
5000 × 12
= 9.2µ
For the simulation model, round of
values Lf = 5mA and Cf = 11µF (Cf1 = Cf2 =
22µF) are taken. The simulation parameters
are shown in table 1.
TABLE 1
Simulation Parameters
The simulation diagram with the
design values is shown in fig. 9 with the
PWM strategy explained in last session. The
waveforms of output voltage and inductor
current is shown in fig. 10. The circuit was
designed for 600V with ideal scenario but
simulation results with settings of practical
scenario shows an output of 578V. So the
efficiency is ɳ = 578/600 = 96.33%. The
maximum inductor current taken for design
was 50A and simulation result shows the
steady-state inductor current around 25A. So
it is under the limit. Waveforms of the half
bridge output voltages Vag and Vbg, and the
output voltage pulse Vab are shown in fig. 11.
Each waveform has three levels of 0, Vo/2
and Vo.
Fig. 9 Simulation Model for Open Loop Control
7. International Journal of Engineering and Techniques
ISSN: 2395-1303
Fig. 10 (a)Output Voltage Vo (b) Inductor current I
The closed loop control is
for 600V output voltage. Fig. 12 shows the
variation made in c for different inputs to
make the output at 600V in open loop control.
It can be seen that there is a linear
relationship between c and Vin. By verifying
the axes points, equation for
relationship is,
= 0.0022 − 0.0038
Fig. 11 Half Bridge Outputs and Output Voltage Pulse (a) V
(c) Vab
This equation is used for closed loop
control. Figure 5.13 shows the simulation
diagram for closed loop control. The
simulation parameters are taken as same as
that of open loop control, except the input
voltage is switched alternatively at different
intervals for showing the variation in input.
Fig.14 shows the switching sequence for the
input. The gate circuit for closed loop control
is shown in fig. 15 Vin is taken and
Fig. 12 (a) Table for Vin vs c (b) Graph showing Linear Relationship
International Journal of Engineering and Techniques - Volume 2 Issue 5, Sep –
http://www.ijetjournal.org
(b) Inductor current IL
The closed loop control is designed
for 600V output voltage. Fig. 12 shows the
variation made in c for different inputs to
make the output at 600V in open loop control.
It can be seen that there is a linear
. By verifying
the axes points, equation for this linear
0038
Fig. 11 Half Bridge Outputs and Output Voltage Pulse (a) Vag (b) Vbg
This equation is used for closed loop
control. Figure 5.13 shows the simulation
diagram for closed loop control. The
simulation parameters are taken as same as
that of open loop control, except the input
voltage is switched alternatively at different
intervals for showing the variation in input.
Fig.14 shows the switching sequence for the
ed loop control
is taken and
vs c (b) Graph showing Linear Relationship
converted to c value. c is again converted to
individual constant values c1, c
Then these values are compared with
amplitude of carrierwave signal to generate
various gate signals. As the input voltage
changes, duty cycle of gate pulses change
accordingly. Fig. 16 shows waveforms for V
Vo and inductor current IL. Input voltage is
varied from 40V to 50V and finally to 6
all cases, after some distortion in transient
state, the value settles to 600V in steady state.
Fig. 13 Simulation Diagram for Closed Loop Control
Fig. 14 Switching Sequence for Input Voltages
Fig. 15 Gate Circuit for Closed Loop Control
Fig.16 Closed Loop Control (a) Input Voltage V
Vo (c) Inductor Current IL
VI. HARDWARE IMPLEMENTATION
– Oct 2016
Page 77
converted to c value. c is again converted to
, c2, c3 and c4.
Then these values are compared with
litude of carrierwave signal to generate
various gate signals. As the input voltage
changes, duty cycle of gate pulses change
accordingly. Fig. 16 shows waveforms for Vin,
. Input voltage is
varied from 40V to 50V and finally to 60V. In
all cases, after some distortion in transient
state, the value settles to 600V in steady state.
Fig. 13 Simulation Diagram for Closed Loop Control
Fig. 14 Switching Sequence for Input Voltages
Fig. 15 Gate Circuit for Closed Loop Control
Fig.16 Closed Loop Control (a) Input Voltage Vin (b) Output Voltage
VI. HARDWARE IMPLEMENTATION
8. International Journal of Engineering and Techniques
ISSN: 2395-1303
The laboratory hardware testing is
done for the open loop control. Fig.17 shows
the prototype. The input is 5V and output is
33.33V. Since it is a low power circuit, low
rating MOSFETs IRF 540 are taken as
controlled switches. The switching frequency
is 5kHz. PIC 16F877A is programmed to
generate the gate pulses to have voltage gain
M = 20/3(this value was chosen as it is easy
to program the corresponding gate pulses).
The diodes are fast recovery diodes 1N4148.
Converter circuit capacitors and inductor are
chosen as per design values. Fig. 18 shows
the input and output voltage waveform. Input
was regulated DC voltage taken from AC
mains using regulator IC 7805 and 4.92V DC
was generated which is near to 5V. For this
input a satisfactory output of 18.6V DC was
obtained. This difference in practical value is
due to the fact that there will be unavoidable
circuit resistance drops and it also leads to
unbalance in charging and discharging of the
two capacitors. When the circuit is of low
power, these errors become prominent. The
efficiency was found to be 56%. Fig. 19
shows the three level operation. 19(a) shows
waveform of Vag and Vbg, the output voltages
of half bridges I and II respectively. Pulse V
is shorter width than Vag. 19(b) shows V
output voltage pulse, which is the difference
of Vag and Vbg.
Fig. 17 Experimental Setup
International Journal of Engineering and Techniques - Volume 2 Issue 5, Sep –
http://www.ijetjournal.org
The laboratory hardware testing is
done for the open loop control. Fig.17 shows
the prototype. The input is 5V and output is
3V. Since it is a low power circuit, low
rating MOSFETs IRF 540 are taken as
controlled switches. The switching frequency
is 5kHz. PIC 16F877A is programmed to
generate the gate pulses to have voltage gain
M = 20/3(this value was chosen as it is easy
ogram the corresponding gate pulses).
The diodes are fast recovery diodes 1N4148.
Converter circuit capacitors and inductor are
chosen as per design values. Fig. 18 shows
the input and output voltage waveform. Input
was regulated DC voltage taken from AC
ains using regulator IC 7805 and 4.92V DC
was generated which is near to 5V. For this
input a satisfactory output of 18.6V DC was
obtained. This difference in practical value is
due to the fact that there will be unavoidable
also leads to
unbalance in charging and discharging of the
two capacitors. When the circuit is of low
power, these errors become prominent. The
efficiency was found to be 56%. Fig. 19
shows the three level operation. 19(a) shows
he output voltages
of half bridges I and II respectively. Pulse Vbg
. 19(b) shows Vab, the
output voltage pulse, which is the difference
Fig.18 (a)Vin (b)Vo
Fig. 19 (a)Vag and Vbg (b)Vab
VII. CONCLUSIONS
The hybrid boost three
converter is explained in this paper, based on
the conventional single-phase diode clamped
three-level inverter. It can not only operate
with transformerless high voltage gain, but
also make the duty cycles of the power
switches closer to 0.5 with the increasing
voltage gain, instead of the extreme duty
cycles. Moreover, a flexible PWM switching
strategy and closed loop control is explained.
In the simulation of open loop control, circuit
was designed to give an output of 600V for
50V input taking the ideal case. Simulation
result shows an output of 578V, with an
efficiency of 96.33. For the simulation of
closed loop control, the switching pulse width
is varied with change in input voltage to
obtain a constant voltage. Simulation for
closed loop control operation with input range
30V - 70V and output 600V has been done. It
was observed that when there is abrupt
change in input, after some distortion in the
transient state, the output voltage set
constant value in steady state. Laboratory
experiment of the circuit with open loop
control has been done. The circuit was
designed for a gain of M = 20/3. For an input
of 4.92V, the output was 18.6V with around
56% efficiency. So the efficiency
higher for higher voltage levels as there will
be unavoidable circuit resistance drops and it
also leads to unbalance in charging and
– Oct 2016
Page 78
Vab
The hybrid boost three-level DC-DC
converter is explained in this paper, based on
phase diode clamped
level inverter. It can not only operate
with transformerless high voltage gain, but
he duty cycles of the power
switches closer to 0.5 with the increasing
voltage gain, instead of the extreme duty
cycles. Moreover, a flexible PWM switching
strategy and closed loop control is explained.
In the simulation of open loop control, circuit
esigned to give an output of 600V for
50V input taking the ideal case. Simulation
result shows an output of 578V, with an
efficiency of 96.33. For the simulation of
closed loop control, the switching pulse width
is varied with change in input voltage to
tain a constant voltage. Simulation for
closed loop control operation with input range
70V and output 600V has been done. It
was observed that when there is abrupt
change in input, after some distortion in the
transient state, the output voltage settles to a
constant value in steady state. Laboratory
experiment of the circuit with open loop
control has been done. The circuit was
designed for a gain of M = 20/3. For an input
of 4.92V, the output was 18.6V with around
56% efficiency. So the efficiency will be
higher for higher voltage levels as there will
be unavoidable circuit resistance drops and it
also leads to unbalance in charging and
9. International Journal of Engineering and Techniques - Volume 2 Issue 5, Sep – Oct 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 79
discharging of the two capacitors and for the
low power circuit, these errors become
prominent.
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